Servo Connections Pushbutton and LED Indicator Connections Connectors. Relay 3 Connection (Optional) Relay 4 Connection (Optional)

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1 Overview The Quad Servo Driver will control 4 turnouts with either DCC command control or manually by pressing a button. The decoder gets its power directly from the track. It uses R/C airplane servos which are ready available and inexpensive. These instructions explain how to install the servos to control turnouts, however, you can control other devices such as semaphores, crossing gates and so forth. Track Connection Voltage Regulator Gets hot! - Keep it ventilated Servo Connections Pushbutton and LED Indicator Connections Connectors LED Programming Jumpers Relay 3 Connection (Optional) Relay 4 Connection (Optional) Relay 1 Connection (Optional) Relay 2 Connection (Optional) Frog Relays (Optional) Installation Install the decoder by placing it near the turnouts you want to control and the fascia here you want to mount the switches. It is not a good idea to place the decoders in some central location and then run long wires from to the turnouts and switches. For one this will mean a lot of wires to be run and, two, this will degrade the current to the servos and finally make the decoder susceptible to electronic noise. Mount the decoder with a couple of wood screws through the mounting holes, or use double sided tape. In some cases you may just want to leave the decoder floating and tack down the wires around the decoder to keep it in place.

2 Make sure the voltage regulator is free to ventilate the excess heat. Although the regulator is quite tough and over-engineered for the demands of the system, it is probably not a good idea to bury the decoder in foam or put tape over it. Connect the decoder to your DCC track bus just as you would connect a piece of track. If you have your system separated into power districts, connect the decoder to the some district as the turnout is connected to. This way when a short occurs on the track near the turnout and turns off the power to the district, the decoder will also be turned off preventing the switch from moving until the problem has been cleared. (As a handy side effect the LEDs on the decoder will all go off and make it easy to determine which power district has the shorted rails). Servos Plug the servos in to the bank of servo connection pins as shown. Servos have three wires, the power leads are black and red and the third, the signal lead is white, brown, yellow or orange depending upon the brand. Plug there servos in so that the signal lead is inboard and the black wire is towards the edge of the board. If you do it incorrectly, it wonʼt hurt anything, but the servo wonʼt move. Button and LED Indicators If you are going to use buttons for manual control then these are installed in the bank of button and LED indicators. The units from Tam Valley Depot have four wires. Connect them so that the white wire is inboard. Even if you plan to control your turnouts only with DCC, it is good to have one set of button and LED indicators for testing, programming and helping with the installation of the servos. You can move it between slots as needed to test each channel. Wire White Yellow Red Green Function Button - pull low to switch state. Logic Signal - Low indicates closed, High, thrown. Can be used for signals. +5 Volt Ground

3 Refer to the schematic for wiring your own buttons and LEDʼs. Any normally open momentary switch can be used. Centering the Servos To aid in installation the servos can be driven to their center position. Place the programming jumper in place and press the button for the servo to be centered. The servo will stay centered until the jumper is removed and the button pressed again. Be certain not to send a DCC accessory command while the programming jumper is on or the address of the servo will be changed (see Address below). Operation The decoder comes from the factory programmed for addresses 1-4. To move a servo, issue a DCC accessory command by entering the address into the DCC system and then issue either a t or c command. On Digitrax systems the accessory commands are accessed with the Switch button. Consult your manual if you are unsure how to issue accessory commands on your system. You can also change the turnout position manually with a button. Simply press the button to toggle the turnout position. If you have installed the LEDs, the LEDs will change to indicate the turnout position. Note that it takes a second or two for the points to move after the command is issued so avoid pressing the button repeatedly. It wonʼt hurt anything but the points may not move to the intended position - in any case the LEDs indicate the position the final position. Programming The decoder is easily programmed in place after mounting. Mount the decoder to your benchwork in such a way that you can reach the programming jumpers after mounting. No programming track is needed - after all you can hardly pick up the decoder and place it on the programming track as it has no wheels... The system ships with two jumpers, one with a handle for taking on and off and a short one for programming the range jumper if used. The decoder responds to accessory (stationary decoder) commands and ignores commands meant for locomotives (i.e. mobile decoders). See your manual for your how to send accessory command with your DCC system if you are unsure.

4 Address To program the address, place the jumper across the Addr pins and issue an accessory command. The decoder will store the address and flash the LED twice to indicate it has been successfully programmed. The decoder uses 4 consecutive addresses starting with 1-4, the next groups are 5-8, 9-12, and so forth. See the table in the appendix for a handy reference for those of us who are algebraically challenged. At each address there are two positions t for thrown and c for closed. Routes The decoder interprets addresses in the range 513 to 1024 as routes. It will drive all 4 of its servos to a set position when it receives a previously programmed route command. This is very handy for setting up a group of turnouts to reach a particular yard track or for reaching a given staging track. Several decoders can share the same route commands so that a given route command can control as many turnouts as needed. The decoder can remember up to 85 route commands. To program a route set all the points in the desired position, put the Addr jumper into position as above, and then issue an accessory command in the range desired. The LED will flash to indicate it has been programmed. The number of flashes indicate the number of routes programmed. If the same address is programmed a second time it will overwrite all the earlier routes at that address. We suggest using the address 513 for storing the home position into all of your decoders. Note: Many DCC systems have their own route programming built in to the controller. You are free to use this system and ignore the route system built into the decoder - or you can use both systems if you wish for different situations - its your railroad. If you find that you want to free the addresses from route commands, contact Tam Valley Depot and we can send you decoders programmed this way.

5 Reverser When you mount the servo, there is a 50:50 chance it will end up driving the turnout to the closed position when the c command is given. If it ends up backwards, it is simple to program the decoder to reverse the servo so that it throws as desired. Put the programming jumper on the Rv pins and then push the button to change the switch to the opposite position and then remove the jumper. The decoder will remember the reversed position in its memory even after turning off the power. Range The range jumper sets the range of movement of the servos from about +/- 15 degrees to Memory The decoder stores its last state in an EEPROM with non-volatile memory. These are fancy words that mean the decoder can remember its last state after the power is turned off. When the power is turned on the points will remain in the same position as when the power was last turned off. If you want to have the turnouts drive to a home position upon power up then it is a simple a matter to program in a route with a single address into all of the decoders so that you can switch them all to the home position. See the section on Routes. Installation of servos We have installed servos using 2 methods by adapting methods commonly used for other types of turnout motors. The first method using a direct drive requires a small hole through the subroadbed under the points. It is the better method because it is nearly invisible from the top. The other method uses a crank through a small tube. It can be added to already existing turnouts by drilling a 1/16 hole. However, there will be a small wire visible after installation.

6 Direct Drive Before gluing down the turnout drill a 3/8 hole directly under the throw bar. If there isnʼt a small hole in the throw bar then drill one. Attach a piece of.020 spring wire to the servo horn as shown. make the wire plenty long to stick up through the hole and through the throw bar - you will snip the excess off later. I used a Z-bend at the bottom and a throttle linkage at the top, but you can attach the wire at the top by threading it through a hole in the horn. Note the bend around the horn attachment screw. This lets you attach the horn after you center the servo (see Centering The Servo above). A piece of servo tape can be used to attach the servo to the bottom of subroadbed. This holds well. However, if you are worried about the tape giving out, two small blocks of wood can be used to attach the servo through its mounting holes after attachment with the tape. Push the wire up through the hole and through the throw bar and then firmly press the tape to attach it. Verify the installation by actuating the servo with the decoder. You can reseat the servo by applying another layer of tape if needed. Another trick is to unscrew the servo horn attachment screw enough to move the servo horn a couple of clicks to one side or the other to optimally position the horn so the points seat firmly at both ends of the throw. Note: It is tempting to use thicker wire than.020. However there is a real danger the stronger wire will actually unseat the turnout or push the rails out of gauge. The servos are more powerful than a slow-motion motor driven machines such as a Tortoise.

7 Tam Valley Depot Quad Servo Turnout Driver Manual Crank Method Start by drilling a 1/16 hole about 3/8 away from the hole in the throw bar. Push a piece of 1/16 tubing through the hole. The length of the tubing should be such that it will stick out about 1/2 below the subroadbed when it is flush with the tie tops at the top. Glue the tubing in place with a dab of white glue. AVOID USING SUPER GLUE NEAR THE POINTS! If you get white glue on the points you can just wash it off - with super glue you may ruin your turnout. Bend a piece of.020 spring wire so that it forms an inverted L (see the illustrations). Push the wire down through the hole and verify that the bends are the right distance to catch the points and move them. If not re-bend until it is right. Cut the bottom of the wire off 1.25 below the bottom of the tube. It is better to make it too long than too short as you can always trim it shorter but you canʼt easily make it longer! Bend the wire over so that it is parallel to the subroadbed. By pushing the wire back and forth you should be able to move the points. Center the points with some styrene blocks. Now you are ready to mount the servo. Again servo tape is recommended but you can add wood blocks later for extra security. Place the horn on the servo so that it will point straight down with the servo centered. slide the servo over the wire so that 3/8 is sticking out the back and firmly seat the tape. Remove the blocking and you should be able to move the servo to both ends of its throw and have the points switch. The range jumper

8 Tam Valley Depot Quad Servo Turnout Driver Manual should be on for the direct drive method to increase the throw range. The wire sticking out the back of the servo horn may catch on the servo body. If so bend it down. Servo Extensions If the wire is too short to reach the decoder after installation, servo extenders in various lengths are available form Tam Valley Depot or at your local R/C hobby shop. Alternatively you can splice in extra lengths of wire. The servos draw very little current so that any wire 26 gauge and above will work well. Frog Wiring If you have purchased the version with the frog relays then you can wire the frog so that the power will switch with the points. There are three contacts for each frog relay - the center one goes to the frog and the outer two go to either rail. The connector can be put on in two ways. One way will short out the booster and trip it when the locomotive crosses the frog. If this happens simply reverse the

9 connector. If you donʼt want to find out by this rather crude test, then a 12V light bulb can be used - when the light bulb is connected between the frog and the rail in contact with the points, then the light bulb should not light. If it does, then reverse the frog connector and verify the light bulb stays dark. Using the Decoder on DC Railroads The decoder can be used to switch turnouts on DC layouts. You will need to supply power to the decoder through the rail connector. The ACC terminals of a power pack can be used or any power source from 7-24V AC or DC will work. Polarity is not important as the bridge rectifier on the decoder board will correctly rectify the voltage. You will need to connect a momentary switch to control the points.

10 Appendix DCC Address Groups 1, 2, 3, 4 5, 6, 7, 8 9, 10, 11, 12 13, 14, 15, 16 17, 18, 19, 20 21, 22, 23, 24 25, 26, 27, 28 29, 30, 31, 32 33, 34, 35, 36 37, 38, 39, 40 41, 42, 43, 44 45, 46, 47, 48 49, 50, 51, 52 53, 54, 55, 56 57, 58, 59, 60 61, 62, 63, 64 65, 66, 67, 68 59, 70, 71, 72 73, 74, 75, 76 77, 78, 79, 80 81, 82, 83, 84 85, 86, 87, 88 89, 90, 91, 92

11 Schematic

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13 For Experts: Updating/Altering the Software In the spirit of the hobby and the open nature of DCC, we have made the software for the decoder available at our web site. The SX microcontroller used in the decoder can be reprogrammed by downloading code from a computer through a USB-Key available from Parallax ( SX chips can be programmed in SX/B, a version of the BASIC language freely available from Parallax.